Absolute Addictive PHYSICS

Friday, 5 December 2014

More than two years after physicists discovered the Higgs boson, there’s still a lot they don’t know about the elusive particle. Now, they want your help to make the next discovery about this particle with a new citizen-science project called Higgs Hunters. That’s right, some of the brainiest physicists in the world would like you to pitch in.

The Higgs boson was discovered at the Large Hadron Collider in Switzerland, the most powerful particle accelerator in the world. It may sound strange that even with this enormous, $5-billion machine, and all the scientific power applied to the data it collects, scientists still need people like you to help. But the human mind is still better than the most sophisticated algorithm at some tasks, and scouring the LHC data for more evidence of the Higgs is one of those.

The data is created when the LHC slams together beams of protons careening at near-light-speed. When the particles collide, they produce a flurry of new particles—including, sometimes, a Higgs boson. But the Higgs can only exist for 10-22seconds before splintering off into more particles, making it really tough to detect. Theorists predicted what some of those particles would be and how they would create a telltale trail of evidence that the LHC’s detectors could then measure. It was by identifying these signatures that physicists concluded that indeed, they had created some Higgs bosons. But there is still much to learn about this particle.

The theory that describes the fundamental particles and how they interact with one another is called the Standard Model. Although it’s been extremely successful at predicting all kinds of particle interactions, physicists know that it’s incomplete. For example, the theory doesn’t include gravity nor does it explain dark matter, the mysterious stuff that makes up almost a quarter of the universe. So physicists have tried to come up with better, more complete theories.

According to some of these new ideas, the Higgs may decay into some other, unknown, exotic particles that don’t carry an electric charge. The problem is that the detectors at the LHC aren’t able to see particles with no charge. However, these theoretical exotic particles may break down into yet more particles that are electrically charged, and can be detected.

Higgs Hunters asks you to go through images like this one, picking out lines that emanate from an off-center point. ATLAS Experiment / Zooniverse

Particles that can be detected leave behind tracks that are measured by the detector, and this data can be translated into pictures like the one on the left. The tracks appear as lines emanating from the center of the picture, the site of the collision.

The theoretical particles with no electric charge don’t leave a track. Instead, they move invisibly away from the center of the collision before they break up into particles that can be detected. Consequently, the tracks left by those particles sprout from an off-center point in the picture. This pattern turns out to be difficult for computers to identify.

That’s where you come in.

People who become Higgs Hunters will look at images and identify and count tracks that emanate from an off-center point. The data will be a mix of real data from the LHC and those produced by computer simulations. By classifying the data by eye, the Hunters will also help the physicists’ computers improve their own algorithms for identifying off-center tracks.

With your help, physicists hope to make some more exciting discoveries. So get hunting.

Tuesday, 2 December 2014

There was a time when states of matter were simple: Solid, liquid, gas.
Then came plasma, Bose -Einstein condensate, supercritical fluid and
more. Now the list has grown by one more, with the unexpected discovery
of a new state dubbed “dropletons” that bear some resemblance to liquids
but occur under very different circumstances.

The discovery occurred when a team at the University of Colorado Joint
Institute for Lab Astrophysics were focusing laser light on gallium
arsenide (GaAs) to create excitons.

Excitons are formed when a photon strikes a material, particularly a
semiconductor. If an electron is knocked loose, or excited, it leaves
what is termed an “electron hole” behind. If the forces of other charges
nearby keep the electron close enough to the hole to feel an
attraction, a bound state forms known as an exciton. Excitons are called
quasiparticles because the electrons and holes behave together as if
they were a single particle.

If this all sounds a bit hard to relate to, consider that solar cells
are semiconductors, and the formation of excitons is one possible step
to the production of electricity. A better understanding of how excitons
form and behave could produce ways to harvest sunlight more
efficiently.

Graduate student Andrew Almand-Hunter was forming biexcitons – two
excitons that behave like a molecule, by focusing the laser to a dot
100nm across and leaving it on for shorter and shorter fractions of a
second.

“But the experiment didn’t behave at all in the way we expected,”
Almand-Hunter said. When the pulses were lasting less than 100
millionths of a second exciton density reached a critical threshold. “We
expected to see the energy of the biexcitons increase as the laser
generated more electrons and holes. But, what we saw when we did the
experiment was that the energy actually decreased!”

The team figured that they had created something other than biexcitons,
but were not sure what. They contacted theorists at
Philipps-University, Marburg who suggested they had made droplets of 4, 5
or 6 electrons and holes, and constructed a model of these dropletons'
behavior.

The dropletons are small enough to behave quantum mechanically, but the
electrons and holes are not in pairs, as they would be if the dropleton
was just a group of excitons. Instead they form a “quantum fog” of
electrons and holes that flow around each other and even ripple like a
liquid, rather than existing as discrete pairs. However, unlike liquids
we are familiar with, dropletons a finite size, outside which the
electron/hole association breaks down.

The discovery has been published in Nature.
Perhaps the most remarkable thing is that the dropletons are stable, by
the standards of quantum physics. While they can only survive inside
solid materials, they last around 25 trillionths of a second, which is
actually long enough for scientists to study the way their behavior is
shaped by the environment. At 200nm wide the dropletons are as large as
very small bacteria – a size that can be seen by conventional
microscopes.

"Classical optics can detect only objects that are larger than their
wavelengths, and we are approaching that limit," Mackillo Kira of
Philipps-University who provided much of the theoretical grounding told Scientific American. "It would be really neat to not only detect spectroscopic information about the dropleton, but to really see the dropleton."

JILA lab leader Professor Steven Cundiff says, “Nobody is going to
build a quantum droplet widget." However, the work could help in the
understanding of systems where multiple particles interact quantum
mechanically.

Friday, 17 January 2014

How it works

Digital cinema has taken place of historical motion picture film projection. Nearly all the multiplex are using digital cinema projection technique now - a - days. Even a single screen theater like Galaxy (Rajkot ,gujrat [INDIA] ) is using the digital cinema projection....

In addition to the equipment already found in a film-based movie
theatre a DCI-compliant digital cinema screen requires a digital
projector and a computer known as a "server".

Movies are supplied to the theatre as a digital file called a Digital Cinema Package(DCP).
For a typical feature film this file will be anywhere between 90 and
300GB of data (roughly two to six times the information of a Blu-ray
disc) and may arrive as a physical delivery on a conventional computer
hard-drive or via Currently (Dec 2013) physical deliveries are most common and have
become the industry standard. Trailers arrive on a separate hard-drive
and range between 200 and 400MB in size.

satellite or fibre-optic broadband.

Regardless of how the DCP arrives it first needs to be copied onto
the internal hard-drives of the server, usually via a USB port, a
process known as "ingesting". DCPs can be, and in the case of feature
films almost always are, encrypted. The necessary decryption keys are
supplied separately, usually as email attachments and then "ingested"
via USB. Keys are time limited and will expire after the end of the
period for which the title has been booked. They are also locked to the
hardware (server and projector) that is to screen the film, so if the
theatre wishes to move the title to another screen or extend the run a
new key must be obtained from the distributor.

The playback of the content is controlled by the server using a
"playlist". As the name implies this is a list of all the content that
is to be played as part of the performance, the playlist will be created
by a member of the theatre's staff using proprietary software that runs
on the server. In addition to listing the content to be played the
playlist also includes automation cues that allow the playlist to
control the projector, the sound system, auditorium lighting, tab
curtains and screen masking (if present) etc. The playlist can be
started manually, by clicking the "play" button on the server's monitor
screen, or automatically at pre-set times.

Digital Cinema Initiatives

Digital Cinema Initiatives (DCI), a joint venture of the six major studios, published the first version (V1.0) of a system specification for digital cinema in July 2005..The main declared objectives of the specification was to define a digital cinema system that would "present a theatrical experience that is better than what one could achieve now with a traditional 35mm Answer Print",
to provide global standards for interoperability such that any
DCI-compliant content could play on any DCI-compliant hardware anywhere
in the world and to provide robust protection for the intellectual
property of the content providers.

Briefly, the specification calls for picture encoding using the ISO/IEC 15444-1 "JPEG2000" (.j2c) standard and use of the CIE XYZ color space at 12 bits per component encoded with a 2.6 gamma
applied at projection. Two levels of resolution for both content and
projectors are supported: 2K (2048×1080) or 2.2 MP at 24 or 48 frames per second,
and 4K (4096×2160) or 8.85 MP at 24 frames per second. The
specification ensures that 2K content can play on 4K projectors and
vica-versa
For the sound component of the content the specification provides for up to 16 channels of uncompressed audio using the "Broadcast Wave" (.wav) format at 24 bits and 48 kHz or 96 kHz sampling.

Playback is controlled by an XML-format Composition Playlist, into an MXF-compliant file at a maximum data rate of 250 Mbit/s. Details about encryption, key management,
and logging are all discussed in the specification as are the minimum
specifications for the projectors employed including the color gamut, the contrast ratio
and the brightness of the image. While much of the specification
codifies work that had already been ongoing in the Society of Motion
Picture and Television Engineers (SMPTE),
the specification is important in establishing a content owner
framework for the distribution and security of first-release motion
picture content.
In addition to DCI's work, the National Association of Theatre Owners (NATO) released its Digital Cinema System Requirements.

The document addresses the requirements of digital cinema systems from
the operational needs of the exhibitor, focusing on areas not addressed
by DCI, including access for the visually impaired and hearing impaired,
workflow inside the cinema, and equipment interoperability. In
particular, NATO's document details requirements for the Theatre
Management System (TMS), the governing software for digital cinema
systems within a theatre complex, and provides direction for the
development of security key management systems. As with DCI's document,
NATO's document is also important to the SMPTE standards effort.

The Society of Motion Picture and Television Engineers (SMPTE)
began work on standards for digital cinema in 2000. It was clear by
that point in time that HDTV did not provide a sufficient technological
basis for the foundation of digital cinema playback. (In Europe and
Japan however, there is still a significant presence of HDTV for
theatrical presentations. Agreements within the ISO standards body have
led to these systems being referred to as Electronic Cinema Systems
(E-Cinema).)

Digital cinema projectors

Only four manufacturers make DCI-approved digital cinema projectors; these are Sony, Barco, Christie and NEC. Except for Sony, who use their own SXRD technology, all use the Digital Light Processing technology developed by Texas Instruments
(TI). Although D-Cinema projectors are similar in principle to digital
projectors used in industry, education and domestic 'home cinemas' they
differ in two important respects: firstly they must conform to the
strict performance requirements of the DCI specification, secondly they
must incorporate anti-piracy devices intended to protect the content
copyright.

For these reasons all projectors intended to be sold to
theaters for screening current release movies must be approved by
the DCI before being put on sale. Because feature films in digital form
are encrypted and the decryption keys are locked to the make, model and
serial number of the projector used, an unapproved projector simply
will not work if an attempt is made to use it to screen current release
feature films from a DCP.

DLP cinema projectors

Three manufacturers have licensed the DLP cinema technology developed by Texas Instruments (TI): Christie Digital Systems, Barco, and NEC.
While NEC is a relative newcomer to Digital Cinema, Christie is the
main player in the U.S. and Barco takes the lead in Europe and Asia.

Initially DCI-compliant DLP projectors were available in 2K only, but
from early 2012, when TI's 4K DLP chip went into full production, DLP
projectors have been available in both 2K and 4K versions. Manufacturers
of DLP-based cinema projectors are now offering 4K upgrades to many of
their more recent 2K models.

Early DLP Cinema projectors, which were deployed primarily in the U.S.,
used limited 1280×1024 resolution or the equivalent of 1.3 MP
(megapixels). Digital Projection Incorporated (DPI) designed and sold a
few DLP Cinema units when TI's 2K technology first debuted but then
abandoned the D-Cinema market while continuing to offer DLP-based
projectors for non-cinema purposes. Although based on the same 2K TI
"light engine" as those of the major players they are so rare as to be
virtually unknown in the industry. They are still widely used for
pre-show advertising but not usually for feature presentations.

TI's technology is based on the use of Digital Micromirror Devices (DMDs).These devices are manufactured from silicon using similar technology to
that of computer memory chips. The surface of these devices is covered
by a very large number of microscopic mirrors, one for each pixel, so a
2K device has about 2.2 million mirrors and a 4K device about 8.8
million. Each mirror vibrates several thousand times a second between
two positions, in one light from the projector's lamp is reflected
towards the screen, in the other away from it. The proportion of the
time the mirror is in each position varies according to the required
brightness of each pixel.

Three DMD devices are used, one for each of the primary colors. Light
from the lamp, usually a Xenon similar to those used in film projectors
with a power between 1 kW and 7 kW, is split by colored filters into
red, green and blue beams which are directed at the appropriate DMD. The
'forward' reflected beam from the three DMMDs is then re-combined and
focused by the lens onto the cinema screen.

Sony SXRD projectors

Alone amongst the manufacturers of DCI-compliant cinema projectors
Sony decided to develop its own technology rather than use TI's DLP
technology. SXRD projectors have only ever been manufactured in 4K form
and, until the launch of the 4K DLP chip by TI, Sony SXRD projectors
were the only 4K DCI-compatible projectors on the market. Unlike DLP
projectors, however, SXRD projectors do not present the left and right
eye images of stereoscopic movies sequentially but use half the
available area on the SXRD chip for each eye image. Thus during
stereoscopic presentations the SXRD projector functions as a 2K
projector.

Telecommunication

Realization and demonstration, on October 29, 2001, of the first digital cinema transmission by satellite in Europe of a feature film by Bernard Pauchonand Philippe Binant.

Live broadcasting to cinemas

Digital cinemas can deliver live broadcasts from performances or events. For example, there are regular live broadcasts to movie theaters of Metropolitan Opera performances. In February 2009, Cinedigm screened the first live multi-region 3D broadcast through a partnership with TNT.
Previous attempts have been isolated to a small number of screens. In
December 2011, the series finale of the BBC dance competition series Strictly Come Dancing was broadcast live in 3D in selected cinemas.

Thursday, 6 June 2013

You’re looking at is the first direct look of an atom’s electron orbits which can be mathematically described by Atom's Real wave function! To take the photo, Scientists utilized A quantum microscope — an incredibly Innovative device that helps scientists to look into the quantum world.!

An orbital structure is the space in an atom that’s occupied by an electron. But describing these super-microscopic properties of matter, scientists have to depend on wave functions — a mathematical way of describing the quantum states of particles, basically, quantum physicists use formulas like the Schrödinger equation to describe these states, often coming up with complex numbers and Strange graphs!

Up until this point, scientists have never been able to actually observe the electron orbit. Trying to get an atom’s exact position or the momentum of its alone electron direct observations have this obstacle of quantum coherence. So to get a full quantum state We need tool that can statistically average many measurements over time And to magnify this results scientists needs the quantum microscope — a device that uses photoionization microscopy to visualize atomic structures directly.

Aneta Stodolna of the FOM Institute for Atomic and Molecular Physics (AMOLF) in the Netherlands describes how she and her team get a picture of the nodal structure of an electronic orbital of a hydrogen atom placed in a static (dc) electric field in Physical Reviw Letter..

After zapping the atom with laser pulses, ionized electrons escaped and followed a particular trajectory to a 2D detector (dual microchannel plate [MCP] detector placed perpendicular to the field itself). There are many trajectories that can be taken by the electrons to reach the same point on the detector, thus Scientist got the set of interference patterns — patterns that shows the nodal structure of the wave function.

And the they have done this by using an electrostatic lens that magnified the outgoing electron wave more than 20,000 times.

Image: Examples of four atomic hydrogen states. The middle column shows the experimental measurements, while the column at right shows the time-dependent Schrödinger equation calculations.

Physicists have long known that quantum mechanics tells a strange connection between quantum particles "Entanglement" In which measuring one particle can instantly set "state," of another particle—even if it's light years away. Now, experiments have shown that they can entangle two photons that don't even exist at the same time even.....!!!

Entanglement is a kind of order that leis within the uncertainty of quantum theory. Suppose you have a quantum particle of light, or photon. It can be polarized so that it either vertically or horizontally. The quantum realm is also hazed over with unavoidable uncertainty, and thanks to such quantum uncertainty, a photon can also be polarized vertically and horizontally at the same time. If you then measure the photon, however, you will find it either horizontally polarized or vertically polarized,

Entanglement can come in if you have two photons. Each can be put into the uncertain vertical-and-horizontal state. However, the photons can be entangled so that their polarizations are correlated even while they remain undetermined. For example, if you measure the first photon and find it horizontally polarized, you'll know that the other photon has instantaneously collapsed into the vertical state and vice versa—no matter how far away it is. Because the collapse happens instantly, Albert Einstein dubbed the effect "spooky action at a distance." It doesn't violate relativity, though: It's impossible to control the outcome of the measurement of the first photon, so the quantum link can't be used to send a message faster than light.

Now Eli Megidish, Hagai Eisenberg, and colleagues at the Hebrew University of Jerusalem have entangled two photons that don't exist at the same time. They start with a scheme known as entanglement swapping. To begin, researchers zap a special crystal with laser light a couple of times to create two entangled pairs of photons, pair 1 and 2 and pair 3 and 4. At the start, photons 1 and 4 are not tangled. But they can be if physicists play the right trick with 2 and 3.

Add caption

The key is that a measurement "projects" a particle into a definite state -- just as the measurement of a photon collapses it into either vertical or horizontal polarization. So even though photons 2 and 3 start out unentangled, physicists can set up a "projective measurement" that asks, are the two in one of two distinct entangled states or the other? That measurement entangles the photons, even as it absorbs and destroys them. If the researchers select only the events in which photons 2 and 3 end up in, say, the first entangled state, then the measurement also entangles photons 1 and 4. (See diagram, top.) The effect is a bit like joining two pairs of gears to form a four-gear chain: Enmeshing to inner two gears establishes a link between the outer two.

In recent years, physicists have played with the timing in the scheme. For example, last year a team showed that entanglement swapping still works even if they make the projective measurement after they've already measured the polarizations of photons 1 and 4. Now, Eisenberg and colleagues have shown thatphotons 1 and 4 don't even have to exist at the same time, as they report in a paper in press at Physical Review Letters.

To do that, they first create entangled pair 1 and 2 and measure the polarization of 1 right away. Only after that do they create entangled pair 3 and 4 and perform the key projective measurement. Finally, they measure the polarization of photon 4. And even though photons 1 and 4 never coexist, the measurements show that their polarizations still end up entangled. Eisenberg emphasizes that even though in relativity, time measured differently by observers traveling at different speeds, no observer would ever see the two photons as coexisting.

The experiment shows that it's not strictly logical to think of entanglement as a tangible physical property, Eisenberg says. "There is no moment in time in which the two photons coexist," he says, "so you cannot say that the system is entangled at this or that moment." Yet, the phenomenon definitely exists. Anton Zeilinger, a physicist at the University of Vienna, agrees that the experiment demonstrates just how slippery the concepts of quantum mechanics are. "It's really neat because it shows more or less that quantum events are outside our everyday notions of space and time."

So what's the advance good for? Physicists hope to create quantum networks in which protocols like entanglement swapping are used to create quantum links among distant users and transmit uncrackable (but slower than light) secret communications. The new result suggests that when sharing entangled pairs of photons on such a network, a user wouldn't have to wait to see what happens to the photons sent down the line before manipulating the ones kept behind, Eisenberg says. Zeilinger says the result might have other unexpected uses: "This sort of thing opens up people's minds and suddenly somebody has an idea to use it in quantum computing or something."

Jenish Patel

Jenish

is a Cisco Certified Internetworking Expert. He is working in the domain of Routing & switching also working with Next Generation Networks implementation.
Apart from that he is actively involved in String Theory Development and Quantum Physics research.